Power liftgate not working on 2003 Navigator

[superdextor]

Hello all. Thanks for taking the time to help troubleshoot.
The liftgate module has 1 code: U2528 (PRNDL Data Mismatch). So far: the module has been swapped to no avail. Could the code have something to do with the transmission module?

 

[Action]

The lift gate does not work unless the transmission is in park.

The code you are getting is saying the lift gate either does not know what gear the transmission is in or thinks the transmission is in a gear other than park. That is a communication problem. The module is fine.

Attached is the best diagram I could find. The shifter closes a switch when in park and sends that signal to the module. The wiring, connectors or the switch is an issue.

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